Thermostat maybe?

Joined
Apr 16, 2011
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17
Location
Winchester, KY
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04 St1300
Last few rides its been in the 70's and i noticed when i shut my St1300 off the fans are running. I checked the antifreeze level and the heat indication is 3 bars but i do feel more heat on my ankles. Do i have a stuck thermostat maybe like 1/2 open? I have a 04 st1300 with 94k miles and first issue.
Thanks
 

Tom Mac 04a

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Do i have a stuck thermostat maybe like 1/2 open
Prob not... the T stat will usu show as a bouncing temp level form 3 to 2 to 1 to 3 to etc, depending on temp and speed. Stuck open shows up more in cooler weather as the bike comes up to temp (3bars) and then drops as you move faster ( more air flow )
Also gas milage goes down a bit.

Now that the weather is getting cooler up north, expect at least a few people finding stuck Stats! :)

BTW, I also have an 04, when I pull in the garage, I hear the fan kick on with the bike at idle... its hot and you not moving is enought to kick it on for a min or so.. normal as long as it's usu not running while moving ( now that its cooler )
 

Mellow

Joe
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You have any ideals?
There is a fan switch/sensor somewhere, I think it's the one that connects to the t-stat housing and I 'think' Tim Graham from Canada was having this issue. He replaced that connector and it seemed to fix the issue. Maybe there's a way to wiggle it and see if the fans come on? It's not real easy to get to.
 
Joined
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There is a fan switch/sensor somewhere, I think it's the one that connects to the t-stat housing and I 'think' Tim Graham from Canada was having this issue. He replaced that connector and it seemed to fix the issue. Maybe there's a way to wiggle it and see if the fans come on? It's not real easy to get to.

This one?
Find number 22,
LINK
 

Igofar

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I've got over a dozen frozen thermostats on my shelf of shame, all of them frozen open, however, I also have found (2) in the last couple months, that were frozen in the closed position. Just saying it MAY be a thermostat failure, but thats easy enough to correct, and you'd be able to check the switch on the REAR of the thermostat housing as well as the ground on the housing cover. You could kill two birds with one stone so to say.
Good luck.
 

Blrfl

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There is a fan switch/sensor somewhere...
The fan in the 1300 is under the control of the ECM, which decides when to run it based on the information it gets from the Engine Coolant Temperature sensor. (That's what's sticking out of the thermostat housing and is the same source that drives the temperature gauge. If it was faulty, the computer would complain.)

I don't think I've ever had mine run after the ignition has been switched off, but I do shut down with the engine switch instead of the ignition. And I've run into other bikes that do.

Anyway, if it runs for more than a minute after you shut off, the first place to look would be for a sticking fan relay. The only other things that could start the fans running are a faulty ECM and a weird short, neither of which are very likely.

--Mark
 
OP
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Apr 16, 2011
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Winchester, KY
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04 St1300
The temp indicator acts normal it warms up and stays on 3 bars and never varies and i really didnt even know the fan was own till i turned it off with the kill button and the fan ran forever like 3 mins or so to cool it down. Maybe its not halfway but near close and that is why the fan is running all the time is my guess. Gas mileage is normal and the only thing i can tell its a little warmer feeling on the ankles.
 
Joined
Mar 29, 2009
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Southwest Ohio
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2007 ST1300
I always shut down with ignition key. It shuts fans off if they are on. My fans will kick on on these cool mornings after I have run 10 miles and stop to get off and unlock a gate at work(probably idles for maybe 2 min, fans come on and run for maybe 1 min or less then shut off). I would hope ecm has preset amount time it will let fans run with engine off. I bet it wouldn't take long for those fans to flatten the battery.:D Btw wouldn't it take a long time for fans to cool off engine not running? ( no circulation of coolant by waterpump ) Just wondering :confused:
 
OP
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Winchester, KY
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04 St1300
Update on the issue. Today it was 82 out and i cranked the St up and let it idel for at least 5 and the fans finally kicked on and ran and the temp bar stay on 3 and the fans with off. So I thought that sounded normal so i took a 80 mile ride. But near th end i had to set at a light and today for the first time ever the temp indicator went to 4 bars. As i traveled back the next 20 miles the bars would go back to 3 then back to 4. Im suspecting a faulty Thermostat. Any ideals?
 

Scooter

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Have you checked the coolant level? And by that I mean going in and removing the radiator cap and not just checking the level in the overflow bottle? Yeah I know, it's a pain in the arse because you need to take off plastic in order to do that...
 

Igofar

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I'm thinking of a few things to check
Low coolant-check level in overflow tank
Low coolant-check radiator as stated above
Defective radiator cap-replace as needed
Cracked vent hose-near radiator cap
Obstructed line-drain/overflow hose
Faulty Thermostat-replace
Or a large air bubble in the radiator-burp air out when checking cap etc.
My money is on a bad thermostat. PM me an email address and I'll email you photos of why I think this.
(I don't know how to post them on this forum yet)
 

Mellow

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Interesting.... Well, not what I figured would fix it but as long s it's fixed that's all that matters.
 
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